Welcome to the Clan Duncan Breeder's Notebook. All of us wear many "hats" as we travel through life. Here in the Breeder's Notebook, I put on two of my professional "hats," those of biologist and scientific illustrator, to bring you thoughts and perspectives from my own personal vision of the Sheltie. These pages are offered in a spirit of inquiry and with a desire to share.

On the first page of the Breeder's Notebook, I offer a look at Sheltie teeth, their functions, and where they are located in the skull.

Our breed, happily, has a "dog-shaped" skull. By this I mean that no gross distortions of the basic canid skull plan are required by the AKC Sheltie Standard. I have examined thousands of coyote skulls and perhaps ten Sheltie skulls. In some cases the skulls of coyote and Sheltie were so similar that it was quite difficult to distinguish one from the other until I looked at the teeth. (Sheltie teeth tend to be smaller. Also, of course, in a Sheltie of excellent breed type, the backskull will be narrower and flatter than that of a coyote, and the zygomatic arches more flattened.) Having a basic dog-shaped skull is good. This means that Sheltie teeth need not be crowded, misaligned, or otherwise adversely affected as we strive for perfection in breed type.

Let's look at a Sheltie skull. Remember, the teeth appear to be larger and longer in a skull than in a live dog, since the gums are not present.

A domestic dog, Canis familiaris, typically has on each side of each jaw the following teeth: three incisors, one canine, four premolars, and two or three molars. Incisors are used for biting and cutting, canines for stabbing and grasping, premolars for holding, and molars for crushing and tearing.

Characteristics that take away from the utility of a structure are called "degenerate characteristics." As a breed Shelties have few degenerate characteristics, compared to many other breeds. For the health of our breed and of our beloved individual Shelties, this is an excellent state of affairs. One degenerate characteristic sometimes seen in Shelties is missing teeth. Of course, a wild canid with missing teeth might be at a disadvantage when capturing and eating prey, so this is not good. In Shelties, the teeth most often found missing are premolars. Also, in many Shelties with full dentition, the first two premolars have been reduced to tiny points of enamel, barely visible above the gums. Having a missing tooth or two will not affect the health of an individual Sheltie, but as a general rule, I suggest that breeders may wish to avoid mating two dogs that have missing teeth, and should watch carefully that teeth in their bloodlines are not being reduced in size to the point where they become invisible or absent.

Another page of this Breeder's Notebook will examine tooth alignment, including bite.